Negative glass and means for holding same



original'mled oct. 1B. 1919 .ifa/nz Patented Oct. 7, 1924.

asians UNITED STATES PATENT GFFICE.

HERMAN C. BOEDICKER, OF NEW YORK, N. Y.

NEGATIVE GLASS AND MEANS FOR HOLDING SAME.

Application led October` 18, 1919, Serial No. 332,082. Renewed January6, 1923.

To all whom. t may concern.'

Be it known that I, HERMAN C. Bonmonnn,

a citizen of the United States, and ya resident of Nevv York, in theborough of Manhattan and State of New York, have invented certain newand useful Improvements in a Negative Glass and Means for Holding Same,of which the following is a speciiication.

One object of myl invention is to provide an improved form of negativeglass of such style that it may be securely held by means positionedentirely back of the from" surface of the negative glass.

Another object is to provide improved means for holding a negative glassfrom a position back of its front surface.

With these and incidental objects in view, the invention consists ofcertain novel features of construction and combination of parts, theessential elements of Which are hereinafter described with reference tothe drawing which accompanies and forms a part of this specication.

In the drawing, Figure l is a fragmentary sectional detail' taken on theline l-l, Figure 2; Figure 2 is a front view of my improved device; andFigure 3 is a longitudinal, sectional view of the clamping means.

This invention relates to an improvement on the negative glass andnegative box shown and described in my co-pending application, SerialNumber 292,980, filed April 26, 1919, and entitled Photolitho machine.

As shown in Figure l, the Wall lv of the negative box is grooved out at2 to receive the rabbeted edge 3 of the negative glass 4.

The rabbeted edge 5 on the top of the glass is adapted to be heldagainst the wall (3 of the negative box by the lip 7 of the clamp 8.

A stop 9 mounted on the Wall lO of the negative box serves to positionthe iaierally when it is placed in the nega ve boi; and it is held tothe face thereof by the clamp 8.

A heavy plate glass ll, similar to that shown in my co-pendingapplication aforesaid, is mounted in the negative box in any suitablemanner to help reinforce the negative glass 4 against the pressureexerted on its face when a photolithograph machine cf a type similar tothat shown in the co-pending application aforesaid is used for directcontact printing.

The clamp S has a plunger i2 hinged at 13 to the wail 6 of the negativebox, and this plunger is adapted to reci arocate in the tube i3,carrying the head 14, one end of which is formed into the pressure lip7,

The plunger l2 has a head l5 on its free end, and the tube 18 has aclosure i6, and the compression spring l? serves to normally hoid theclamp in a retracted position and thus furnishes a pressure to hold thelip i' against the rabbeted edge 5 of the negative glass 4. f

I find that this construction of negative glass is more stable than theone using abevelled edge, as shown in my co-pending ap plicationaforesaid, and also that the clamping against the straight face of therabbeted edge by the lip 'T holdsv the nep-satire .is more securely thanwhen I clamped on the bevelled edge of the glass.

While I have described my invention and illustrated it in one particulardesign, I do not Wish it understood that I limit myself to thisconstruction, as it is evident that the application of the invention maybe varied in many ways Within the scope of the following claims:

Claims:

l. The combination of a negative glass having two edges thereofrabbeted, a negative box having a groove positioned along one sidethereof to receive one of said rabbeted edges, and clamping meanssupported on another face of said negative box for clamping the other ofsaid rabbeted edges.

2. The combination of a negative glass having two rabbeted edges, anegative bei; having its front formed to receive the baci-1 face of saidnegative glass, means on said negative box to receive one ef therabbeted edges of said negative glass, and spring clamping means forclamping the other of said rabbeted edges, to draw the back surface ofsain negative glass securely against the front of said negative box.

HERMAN C, BOEDICKER.

